From 3a6431db5461b88e691d770abdba6a2793ef699d Mon Sep 17 00:00:00 2001
From: David Smith <smithdc@gmail.com>
Date: Tue, 3 Aug 2021 17:27:57 +0100
Subject: [PATCH] Refs #29205 -- Added MultiValueField test for rendering of
 optional subfields.

---
 tests/forms_tests/tests/test_forms.py | 40 +++++++++++++++++++++++++--
 1 file changed, 37 insertions(+), 3 deletions(-)

diff --git a/tests/forms_tests/tests/test_forms.py b/tests/forms_tests/tests/test_forms.py
index 0fe07492940..212af2ad147 100644
--- a/tests/forms_tests/tests/test_forms.py
+++ b/tests/forms_tests/tests/test_forms.py
@@ -10,9 +10,10 @@ from django.forms import (
     BooleanField, CharField, CheckboxSelectMultiple, ChoiceField, DateField,
     DateTimeField, EmailField, FileField, FileInput, FloatField, Form,
     HiddenInput, ImageField, IntegerField, MultipleChoiceField,
-    MultipleHiddenInput, MultiValueField, NullBooleanField, PasswordInput,
-    RadioSelect, Select, SplitDateTimeField, SplitHiddenDateTimeWidget,
-    Textarea, TextInput, TimeField, ValidationError, forms,
+    MultipleHiddenInput, MultiValueField, MultiWidget, NullBooleanField,
+    PasswordInput, RadioSelect, Select, SplitDateTimeField,
+    SplitHiddenDateTimeWidget, Textarea, TextInput, TimeField, ValidationError,
+    forms,
 )
 from django.forms.renderers import DjangoTemplates, get_default_renderer
 from django.forms.utils import ErrorList
@@ -3102,6 +3103,39 @@ Good luck picking a username that doesn&#x27;t already exist.</p>
         with self.assertRaisesMessage(ValidationError, "'Enter a valid country code.'"):
             f.clean(['61', '287654321', '123', 'Home'])
 
+    def test_multivalue_optional_subfields_rendering(self):
+        class PhoneWidget(MultiWidget):
+            def __init__(self, attrs=None):
+                widgets = [TextInput(), TextInput()]
+                super().__init__(widgets, attrs)
+
+            def decompress(self, value):
+                return [None, None]
+
+        class PhoneField(MultiValueField):
+            def __init__(self, *args, **kwargs):
+                fields = [CharField(), CharField(required=False)]
+                super().__init__(fields, *args, **kwargs)
+
+        class PhoneForm(Form):
+            phone1 = PhoneField(widget=PhoneWidget)
+            phone2 = PhoneField(widget=PhoneWidget, required=False)
+            phone3 = PhoneField(widget=PhoneWidget, require_all_fields=False)
+            phone4 = PhoneField(
+                widget=PhoneWidget, required=False, require_all_fields=False,
+            )
+
+        form = PhoneForm(auto_id=False)
+        self.assertHTMLEqual(
+            form.as_p(),
+            """
+            <p>Phone1:<input type="text" name="phone1_0" required><input type="text" name="phone1_1" required></p>
+            <p>Phone2:<input type="text" name="phone2_0"><input type="text" name="phone2_1"></p>
+            <p>Phone3:<input type="text" name="phone3_0" required><input type="text" name="phone3_1"></p>
+            <p>Phone4:<input type="text" name="phone4_0"><input type="text" name="phone4_1"></p>
+            """,
+        )
+
     def test_custom_empty_values(self):
         """
         Form fields can customize what is considered as an empty value